Chuck device

ABSTRACT

A chuck device in which a rotary sleeve provided to a main body is rotated, and by rotation of an annular rotary body which rotates together with the rotary sleeve, jaws screwed together with the rotary body are expanded, contracted, advanced, and retracted, and a tool is gripped by the jaws; the chuck device comprising a retaining engaging body for engaging with the rotary body and preventing the rotary sleeve from coming out of the rotary body; wherein the retaining engaging body is provided to be fixed to a proximal end side of the rotary sleeve; a rotation transmission part for directly or indirectly transmitting the rotation of the rotary sleeve to the rotary body is provided to the retaining engaging body; and the rotation of the rotary sleeve is transmitted to the rotary body via the retaining engaging body, and the rotary body rotates together with the rotary sleeve.

TECHNICAL FIELD

The present invention relates to a chuck device.

BACKGROUND ART

In a conventional chuck device as disclosed in Patent Document 1, arotary sleeve provided to a main body is rotated, and by the rotation ofa rotary nut which rotates together with the rotary sleeve, jaws whichare screwed together with the rotary nut are expanded, contracted, andslid, and a tool is gripped by the jaws.

Known structures for preventing disengagement between the rotary nut orthe main body and the rotary sleeve in such a chuck device include astructure such as the one disclosed in Patent Document 1, for example,in which a C-shaped stop ring (retaining ring) is placed in a grooveprovided to the internal peripheral surface of the proximal end side ofthe rotary sleeve, and the (shape-retaining ring for retaining the shapeof the) rotary nut is engaged in the stop ring and retained; and astructure such as the one disclosed in Patent Document 2, in which astop ring the same as the one described above is placed in a grooveprovided to the internal peripheral surface of a distal-end opening of arotary sleeve (external cover part) in which jaws retract, and the mainbody (chuck body) is engaged in the stop ring and retained. The rotarynut is annular and fitted in the main body, and disengagement of therotary sleeve is prevented by retaining either the rotary nut or themain body.

PRIOR ART DOCUMENTS Patent Documents

[Patent Document 1] Japanese Patent No. 4053301

[Patent Document 2] Japanese Laid-open Patent Publication No. 9-225713

DISCLOSURE OF THE INVENTION Problems that the Invention is Intended toSolve

The present invention was developed as a result of research intodeveloping, in view of the foregoing conditions, a disengagementprevention structure whereby a stronger linkage is achieved between therotary nut (rotary body) or the main body and the rotary sleeve, and anobject of the present invention is to provide a practical chuck devicewhich is not only capable of providing more reliable and stableretention between the rotary body or the main body and the rotarysleeve, but also has excellent mass-productivity.

Means for Solving the Problems

The main points of the present invention are described below withreference to the attached drawings.

The present invention relates to a chuck device in which a rotary sleeve2 provided to a main body 1 is rotated, and the rotation of an annularrotary body 3 which rotates together with the rotary sleeve 2 causesjaws 4 screwed together with the rotary body 3 to expand, contract,advance, and retract, and a tool to be gripped by the jaws 4; the chuckdevice characterized in comprising a retaining engaging body 5 forengaging with the rotary body 3 or the main body 1 and preventing therotary sleeve from coming out of the rotary body 3 or the main body 1;wherein the retaining engaging body 5 is provided so as to be fixed to aproximal end side of the rotary sleeve 2; a rotation transmission partfor directly or indirectly transmitting the rotation of the rotarysleeve 2 to the rotary body 3 is provided to the retaining engaging body5; and the rotation of the rotary sleeve 2 is transmitted to the rotarybody 3 via the retaining engaging body 5, and the rotary body 3 rotatestogether with the rotary sleeve 2.

The present invention also relates to a chuck device in which a rotarysleeve 2 provided to a main body 1 is rotated, and the rotation of anannular rotary body 3 which rotates together with the rotary sleeve 2causes jaws 4 screwed together with the rotary body 3 to expand,contract, advance, and retract, and a tool to be gripped by the jaws 4;the chuck device characterized in comprising a retaining engaging body 5for engaging with the rotary body 3 or the main body 1 and preventingthe rotary sleeve from coming out of the rotary body 3 or the main body1; wherein the retaining engaging body 5 is provided so as to be fixedto a proximal end side of the rotary sleeve 2; a middle sleeve body 10for fitting with the rotary body 3 is provided on the inside of therotary sleeve 2; a rotation transmission part for transmitting therotation of the rotary sleeve 2 to the rotary body 3 via the middlesleeve body 10 is provided to the retaining engaging body 5; and therotation of the rotary sleeve 2 is transmitted to the rotary body 3 viathe retaining engaging body 5 and the middle sleeve body 10, and therotary body 3 rotates together with the rotary sleeve 2.

The present invention also relates to a chuck device, wherein, in thechuck device according to a second aspect, the retaining engaging body 5is provided with a co-rotation fitting part 7 as the rotationtransmission part, for fitting with a recessed part 11 or projected partprovided to the middle sleeve body 10.

The present invention also relates to a chuck device, wherein, in thechuck device according to a third aspect, the retaining engaging body 5comprises a cylindrical fixed part 8 fixed to the rotary sleeve 2; aprotruding part 6 for preventing the rotary sleeve 2 from coming out ofthe rotary body 3 or the main body 1, the protruding part 6 protrudingtoward the inside of the cylindrical fixed part 8 and abutting therotary body 3 or the main body 1; and the co-rotation fitting part 7provided to said cylindrical fixed part 8.

The present invention also relates to a chuck device, wherein, in thechuck device according to a fourth aspect, the protruding part 6 extendsin a direction intersecting with the rotational axis of the rotarysleeve 2.

The present invention also relates to a chuck device, wherein, in thechuck device according to a fifth aspect, the co-rotation fitting part 7extends in the rotational axis direction of the rotary sleeve 2.

The present invention also relates to a chuck device, wherein, in thechuck device according to a sixth aspect, the protruding part 6 and theco-rotation fitting part 7 are provided so that the extension directionsthereof intersect each other at substantially a right angle.

The present invention also relates to a chuck device, wherein, in thechuck device according to a seventh aspect, the cylindrical fixed part 8is press-fitted on an internal peripheral surface of the rotary sleeve 2so as to be fixed to the rotary sleeve 2.

The present invention also relates to a chuck device, wherein, in thechuck device according to an eighth aspect, the retaining engaging body5 is made of metal, and the protruding part 6, the co-rotation fittingpart 7, and the cylindrical fixed part 8 are formed so as to beintegrally molded.

The present invention also relates to a chuck device, wherein, in thechuck device according to any of a third through ninth aspect, themiddle sleeve body 10 is provided with a rotation-transmitting engagingpart 9 disposed between a plurality of projections 14 a, 14 b, 14 c, 14d provided to the rotary body 3, the rotation-transmitting engaging part9 engaging with the projections 14 a, 14 b, 14 c, 14 d and transmittingthe rotation of the rotary sleeve 2 to the rotary body 3.

The present invention also relates to a chuck device, wherein, in thechuck device according to a tenth aspect, the rotary sleeve 2 is made ofmetal, and the middle sleeve body 10 is made of synthetic resin.

The present invention also relates to a chuck device, wherein, in thechuck device according to an eleventh aspect, the rotary body 3comprises an annular nut body 12 formed by providing a plurality ofsplit nut bodies in a connected row arrangement, and a shape-retainingring 13 for retaining the shape of the nut body 12.

The present invention also relates to a chuck device in which a rotarysleeve 2 provided to a main body 1 is rotated, and the rotation of anannular rotary body 3 which rotates together with the rotary sleeve 2causes jaws 4 screwed together with the rotary body 3 to expand,contract, advance, and retract, and a tool to be gripped by the jaws 4;the chuck device characterized in comprising a retaining engaging body 5for engaging with the rotary body 3 or the main body 1 and preventingthe rotary sleeve from coming out of the rotary body 3 or the main body1; wherein the retaining engaging body 5 is provided so as to be fixedto a proximal end side of the rotary sleeve 2; a rotation transmissionpart for transmitting the rotation of the rotary sleeve 2 to the rotarybody 3 is provided to the retaining engaging body 5; and the rotation ofthe rotary sleeve 2 is transmitted to the rotary body 3 via theretaining engaging body 5, and the rotary body 3 rotates together withthe rotary sleeve 2.

The present invention also relates to a chuck device, wherein, in thechuck device according to a thirteenth aspect, the retaining engagingbody 5 is provided with a co-rotation fitting part 7 as the rotationtransmission part, for fitting with a recessed part 11 or projected partprovided to the rotary body 3.

The present invention also relates to a chuck device, wherein, in thechuck device according to a fourteenth aspect, the rotary body 3comprises an annular nut body 12 formed by providing a plurality ofsplit nut bodies in a connected row arrangement, and a shape-retainingring 13 for retaining the shape of the nut body 12; and the recessedpart 11 or projected part is provided to the shape-retaining ring 13.

The present invention also relates to a chuck device, wherein, in thechuck device according to a fifteenth aspect, the recessed part 11 orprojected part is provided to a flange part 40 provided to an upper endpart of the shape-retaining ring 13.

Effect of the Invention

Through the present invention configured as described above, a practicalchuck device is provided which is not only capable of providing morereliable and stable retention between the rotary body or the main bodyand the rotary sleeve, but also has excellent mass-productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is rough front view showing a partial cut-away view of thepresent example;

FIG. 2 is a rough perspective view showing the main body on which therotary body is fitted in the present example;

FIG. 3 is a rough exploded perspective view showing the middle sleevebody and the dropout prevention body of the present example;

FIG. 4 is a rough perspective view showing the middle sleeve body andthe dropout prevention body of the present example;

FIG. 5 is a rough bottom view showing the dropout prevention body of thepresent example;

FIG. 6 is a sectional view along line W-W of FIG. 1, showing theoperation of the present example;

FIG. 7 is a sectional view along line X-X of FIG. 1, showing theoperation of the present example;

FIG. 8 is a rough front view showing a partial cut-away view of anotherexample; and

FIG. 9 is a rough exploded perspective view showing the shape-retainingring and the dropout prevention body of another example.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred examples of the present invention are briefly described belowwith reference to the diagrams while indicating the effects of thepresent invention.

A retaining engaging body 5 for preventing a rotary sleeve 2 from comingout of a rotary body 3 or a main body 1 is provided so as to be fixed tothe rotary sleeve 2, and even when impact or vibration occurs duringwork using a gripped tool, the rotary sleeve 2 can reliably be preventedfrom separating from the rotary body 3 or the main body 1.

By providing a rotation transmission part to the retaining engaging body5, the retaining engaging body 5 can be endowed not only with retainingand engaging effects, but also with rotation-transmitting effects, andsuch a simple configuration enables rotation of the rotary sleeve 2 tobe transmitted to the rotary body 3.

Furthermore, by providing a co-rotation fitting part 7 as the rotationtransmission part to the retaining engaging body 5, for example, it ispossible to provide a middle sleeve body 10, for example, and even whenthe rotary sleeve 2 is made of metal in order to increase the strengthof the external peripheral part, the middle sleeve body 10 is made ofsynthetic resin, the inside surface and other parts of the middle sleevebody 10 can easily be molded in the desired shape, and accordinglyexcellent workability and mass-productivity are obtained.

EXAMPLES

Specific examples of the present invention are described below withreference to the diagrams.

The present example is of a chuck device in which a rotary sleeve 2 isrotated, whereby a plurality of jaws 4 inserted in a hole 20 provided atthe distal end of the main body 1 are expanded, contracted, and slid,and a tool is gripped by the jaws 4. In the chuck device, annularratchet teeth 21 are provided to the main body 1, an annular rotary body3 which rotates together with the rotary sleeve 2 is screwed togetherwith the jaws 4 and fitted in the main body 1 on the inside of therotary sleeve 2, a detachable engaging spring for engaging with theratchet teeth 21 is provided on the outside of the ratchet teeth 21, theengaging spring is provided so as to rotate on the periphery of theratchet teeth 21 in conjunction with the rotation of the rotary body 3,the engaging spring is attached to the rotary body 3 by arecessed/projected fitting means, and a maintaining part 23 is providedfor maintaining the state in which the ratchet teeth 21 and the engagingspring are engaged, and the state in which the ratchet teeth 21 and theengaging spring are disengaged. The chuck device is configured having aretaining engaging body 5 for engaging with the rotary body 3 or themain body 1 and preventing the rotary sleeve 2 from coming out of therotary body 3 or the main body 1, wherein the retaining engaging body 5is provided so as to be fixed to the proximal end of the rotary body 3with respect to the rotary sleeve 2, a middle sleeve body 10 for fittingwith the rotary body 3 is provided between the rotary sleeve 2 and themain body 1, a co-rotation fitting part 7 for fitting with a recessedpart 11 or projected part provided to the middle sleeve body 10 isprovided to the retaining engaging body 5, the rotation of the rotarysleeve 2 is transmitted to the rotary body 3 via the retaining engagingbody 5 and the middle sleeve body 10, and the rotary body 3 rotatestogether with the rotary sleeve 2.

The present example is of a specific implementation of the presentinvention as a chuck device used in a so-called hammer drill, vibrationdrill, drill driver, or other rotary power tool for imparting vibrationor impact, and a coupling hole 36 for coupling with the main shaft ofthe rotary power tool is provided to the proximal end part of the mainbody 1.

The main body 1 is made using iron, steel, stainless steel, or othermetal; aluminum, magnesium, titanium, or other nonferrous metal; analloy of these metals; or a synthetic resin, fiber-reinforced resin, orthe like. The main body 1 is made of steel in the present example.

As shown in FIG. 1, three jaws 4 are provided at an angle in the hole 20formed in the main body 1, and the annular rotary body 3 screwedtogether with a threaded part 15 formed on the external surface of thejaws 4 is provided so as to be fitted on the jaws 4.

The rotary body 3 is composed of a plurality of split nut bodies 12split in the peripheral direction, and a shape-retaining ring 13 forretaining the shape of the plurality of split nut bodies 12 (wherein thesplit nut bodies 12 and the shape-retaining ring 13 rotate in integralfashion). The reference numeral 17 in the drawings refers to a steelball, 18 to a steel ball holder, and 19 to an O-ring. A configurationemploying split nut bodies is not limiting, and a nut body that isintegrated in advance may also be used.

A middle sleeve body 10 made of synthetic resin is fitted on the distalend side of the rotary body 3 with respect to the main body 1. As shownin FIGS. 3, 6, and 7, the middle sleeve body 10 is provided with arotation-transmitting engaging part 9 disposed between a plurality ofprojections 14 a, 14 b, 14 c, 14 d provided so as to protrude to thedistal-end side from the split nut bodies 12, the rotation-transmittingengaging part 9 engaging with the projections 14 a, 14 b, 14 c, 14 d andtransmitting the rotation of the rotary sleeve 2 to the rotary body 3.In the present example, rotation-transmitting engaging parts 9 areprovided as a facing pair. As shown in FIGS. 3 and 4, recessed parts 11for fitting with co-rotation fitting parts 7 of the retaining engagingbody 5 are provided at predetermined intervals in the peripheraldirection at the proximal end of the middle sleeve body 10.

In the present example, a configuration is adopted in which the rotarysleeve 2 is rotated, the rotation is transmitted to the nut bodies 12,and the rotary body 3 is rotated, but a configuration may also beadopted in which the rotation of the rotary sleeve 2 is transmitted tothe shape-retaining ring 13 to rotate the rotary body 3.

An engaging spring body is attached in a co-rotating state to theprojections 14 a, 14 b, 14 c, 14 d provided to the nut bodies 12 of therotary body 3. Annular ratchet teeth 21 for meshing with a distal-endengaging part of the engaging spring body are formed in the main body 1at the distal-end side of the rotary body 3. The ratchet teeth 21 may beformed directly in the main body 1, or may be formed separately from themain body 1 by a hard member 13 having high hardness, e.g., a stainlesssteel member. Engagement of the ratchet teeth 21 and the distal-endengaging part produces a state in which the nut bodies 12 can rotate inonly one direction (non-reversible state). The engaging spring body andthe ratchet teeth are described in detail hereinafter.

The rotary sleeve 2 made of metal (steel) is fitted on the main body 1on which the rotary body 3 and the middle sleeve body 10 are fitted. Therotary sleeve 2 is not limited to being made of metal, and may be madeof resin.

The annular retaining engaging body 5 made of metal (steel) ispress-fitted on the proximal-end side of the rotary sleeve 2.Specifically, the retaining engaging body 5 has a cylindrical fixed part8 formed by an annular thin plate having a slightly larger diameter thanan internal peripheral surface of the proximal-end side of the rotarysleeve 2, which has a substantially constant diameter. The middle sleevebody 10 is fitted on the main body 1 to which the rotary body 3 isprovided, the rotary sleeve 2 is fitted on the main body 1 on which themiddle sleeve body 10 is fitted, the retaining engaging body 5 isinserted from the proximal-end side of the rotary sleeve 2, and thecylindrical fixed part 8 is press-fitted to the rotary sleeve at aposition on the proximal-end side with respect to the rotary body 3, andis thereby provided so as to be fixed to the rotary sleeve 2. Since therotary sleeve 2 and the retaining engaging body 5 are both made ofmetal, the retaining engaging body 5 is very securely fixed by thepress-fitting. The cylindrical fixed part 8 is also not limited to beingpress-fitted at a position on the proximal-end side with respect to therotary body 3, i.e., a position on the proximal-end side with respect tothe site at which the nut bodies 12 of the rotary body 3 and thethreaded part 15 of the jaws 4 are screwed together, for example, andthe cylindrical fixed part 8 may also be press-fitted at a position onthe distal-end side (or at substantially the same position as thethreaded part) with respect to the threaded part.

The retaining engaging body 5 is composed of the cylindrical fixed part8 fixed to the rotary sleeve 2; protruding parts 6 for protruding towardthe inside of the cylindrical fixed part 8 and abutting the rotary body3 or the main body 1 to prevent the rotary sleeve 2 from coming out ofthe rotary body 3 or the main body 1; and the co-rotation fitting parts7 for transmitting the rotation of the rotary sleeve 2 provided to thecylindrical fixed part 8. Specifically, the protruding parts 6 protrudea predetermined amount toward the inside of the rotary sleeve 2 from thelower end part of the cylindrical fixed part 8, and are configured so asto abut the (shape-retaining ring 13 of the) rotary body 3. Theprotruding parts 6 are not limited to abutting the rotary body 3, andmay also be configured so as to abut the main body 1, but when theretaining engaging body 5 (protruding parts 6) touches the main body 1,a loss due to friction occurs between the retaining engaging body 5 andthe main body 1 (not necessarily meaning that there is always contactwith the protruding parts 6).

The protruding parts 6 of the retaining engaging body 5 are plate-shapedand extend in a direction which intersects with the rotational axis ofthe rotary sleeve 2 (the direction orthogonal to the rotational axis ofthe rotary sleeve 2), and the distal-end surfaces of the protrudingparts 6 are set as the surfaces that abut the rotary body 3 or the mainbody 1.

The co-rotation fitting parts 7 of the retaining engaging body 5 arealso plate-shaped, and extend in the rotational axis direction of therotary sleeve 2 (the direction parallel to the rotational axis of therotary sleeve 2) from the fixed part 8. The same number of co-rotationfitting parts 7 as recessed parts are provided at predeterminedintervals at positions corresponding to the recessed parts 11 providedin the proximal-end part of the middle sleeve body 10, and theprotruding parts 6 are provided between the co-rotation fitting parts 7.The co-rotation fitting parts 7 are provided via a shoulder so as not totouch the internal peripheral surface of the rotary sleeve 2 and theshape-retaining ring 13 of the rotary body 3. The co-rotation fittingparts 7 are designed to have substantially the same width as therecessed parts 11.

As shown in FIGS. 3 through 5, the retaining engaging body 5 of thepresent example is configured so that equal numbers of the protrudingparts 6 extending in a direction that intersects with the rotationalaxis of the rotary sleeve 2, and the co-rotation fitting parts 7extending in the rotational axis direction of the rotary sleeve 2 in thecylindrical fixed part 8 are arranged in alternating fashion in theperipheral direction of the fixed part 8 so that the extensiondirections thereof intersect each other at a substantially right angle.

The retaining engaging body 5 is formed by integrally molding theprotruding parts 6, the co-rotation fitting parts 7, and the cylindricalfixed part 8.

The co-rotation fitting parts 7 of the retaining engaging body 5 whichis provided so as to be fixed to the rotary sleeve 2 thereby cause themiddle sleeve body 10 to rotate integrally with the rotary sleeve 2, therotation of the middle sleeve body 10 is transmitted to the (nut bodies12 of the) rotary body 3 via the rotation-transmitting engaging parts 9,and the jaws 4 can be expanded, contracted, advanced, and retracted bythe rotation of the rotary sleeve 2.

In the present example, the retaining engaging body 5 is configured soas to indirectly transmit the rotation of the rotary sleeve 2 to therotary body 3 via the middle sleeve body 10, but a configuration mayalso be adopted in which the middle sleeve body 10 is not provided, arotation transmission part (co-rotation fitting parts 7) is directlyfitted with recessed parts 11 or projected parts (the same as those ofthe middle sleeve body 10 described above) provided to the proximal-endpart of the rotary body 3 (the nut bodies 12 or the shape-retaining ring13), and the rotation of the rotary sleeve 2 is thus transmitted. Inthis case, not providing a ratchet mechanism allows a simplerconfiguration when the application does not require prevention ofloosening, and the work of assembly is also facilitated.

For example, a configuration may be adopted in which a flange part 40 isprovided at the upper end part of the shape-retaining ring 13, notchedparts (recessed parts 11) having substantially the same width as theco-rotation fitting parts 7 or a slightly larger width than theco-rotation fitting parts 7 are formed at substantially the sameinterval as that of the co-rotation fitting parts 7 at the distal end ofthe flange part 40, and the co-rotation fitting parts 7 are fitted withthe notched parts, as in the other examples shown in FIGS. 8 and 9. Inthis case, the rotation of the rotary sleeve 2 can be directlytransmitted to the rotary body 3 without the intervention of the middlesleeve body 10.

In the present example, the co-rotation fitting parts 7 are employed asrotation transmission parts to transmit the rotation of the rotarysleeve 2 to the rotary body 3, but a configuration may also be adoptedin which a portion of the retaining engaging body 5 is press-fitted withthe middle sleeve body 10 (shape-retaining ring 13 of the rotary body3), for example, so that the middle sleeve body 10 (rotary body 3) andthe rotary sleeve 2 rotate together and the rotation of the rotarysleeve 2 is transmitted to the rotary body 3 (the press-fitted part atwhich the retaining engaging body 5 is press-fitted may be the rotationtransmission part).

The engaging spring body and the ratchet teeth will next be describedwith reference to FIGS. 6 and 7.

The engaging spring body is made of metal (iron or steel), and isdisposed on the periphery of the ratchet teeth 21 so as to be supportedby the internal surface of the middle sleeve body 10. The rotationalforce of the rotary sleeve 2 is transmitted in the same manner even whentransmitted through the shape-retaining ring 13.

The engaging spring body of the present example is composed of twoengaging spring bodies 22, 23. One engaging spring body 22 has theoperation of engaging with the ratchet teeth 21, and the other engagingspring body 23 has the operation of maintaining the engaging spring body22 in a predetermined position by maintaining the position of the rotarysleeve 2. In the present example thus configured, the operation ofengaging with the ratchet teeth 21, and the operations of maintainingand releasing engagement with the ratchet teeth 21 are handled byseparate springs, but a configuration may also be adopted in which theseoperations are handled by a single engaging spring body.

The engaging spring body 22 is provided with two projections 25, 26 anda distal-end engaging part 24 for engaging with the ratchet teeth 21.The engaging spring body 22 is attached so as to rotate together withthe nut bodies 12 by the projections 25, 26 of the engaging spring body22 and the (recessed parts of the) projections 14 a, 14 b of the nutbodies 12.

The engaging spring body 23 is provided with three projections 27, 28,29. The engaging spring body 23 is attached so as to rotate togetherwith the nut bodies 12 by the projections 27, 28, 29 of the engagingspring body 23 and the (recessed parts of the) projections 14 b, 14 c,14 d of the nut bodies 12.

Consequently, since the engaging spring bodies 22, 23, therotation-transmitting engaging parts 9, and the projections 14 a, 14 b,14 c, 14 d are arranged on the same circumference, an accordinglycompact design can be obtained.

The engaging spring bodies 22, 23 and the nut bodies 12 may be attachedby any configuration insofar as the engaging spring bodies 22, 23 andthe nut bodies 12 rotate together. In the present example, the engagingspring bodies 22, 23 are attached to the nut bodies 12 by arecessed/projected fitting means, but the engaging spring bodies 22, 23may also be attached to the shape-retaining ring 13 by arecessed/projected fitting means.

An interposing body 35 for ensuring reliable release of engagementbetween the distal-end engaging part 24 of the engaging spring body 22and the ratchet teeth 21 is provided on the internal surface of themiddle sleeve body 10, the distal-end engaging part 24 is received by atapered surface at the distal end of the interposing body 35, andengagement (meshing) between the distal-end engaging part 24 and theratchet teeth 21 is reliably released.

The internal surface of the middle sleeve body 10 is provided with animmobilizing part 32 for immobilizing the distal-end engaging part 24 ofthe engaging spring body 22 and maintaining an engaged state between thedistal-end engaging part 24 and the ratchet teeth 21.

The middle sleeve body 10, the distal end of which is received by themain body 1, is fitted on the nut bodies 12, and the middle sleeve body10 is configured so as to rotate together with the nut bodies 12, but torotate a predetermined angle in relation to the nut bodies 12 when apredetermined load is placed on the rotation of the nut bodies 12.

The rotation of the middle sleeve body 10 a predetermined angle inrelation to the nut bodies 12 is between the projection 14 a and theprojection 14 b, i.e., L in FIG. 6. Through this configuration, when themiddle sleeve body 10 rotates together with the rotary sleeve 2 and aload occurs, projections 33, 34 of the middle sleeve body 10 surmountthe projections 30, 31 against the spring force of the engaging springbody 23, the end surface of the rotation-transmitting engaging part 9between the projections 14 a, 14 b abuts the end surface M of theprojection 14 b (likewise, the end surface of the rotation-transmittingengaging part 9 between the projections 14 c, 14 d abuts the end surfaceN of the projection 14 d), the middle sleeve body 10 (rotary sleeve 2)and the nut bodies 12 are integrated, and tightening occurs.

Insofar as the presence of the projections 33, 34 prevents theprojections 33, 34 from surmounting the projections 30, 31 of theengaging spring body 23 against the spring force, the rotary sleeve 2does not rotate in the slackening direction, and an accordingly reliableanti-loosening effect is demonstrated. The anti-loosening force can beset by the spring force of the engaging spring bodies 22, 23, andparticularly by the shape of the projections 33, 34 and the projections30, 31.

Furthermore, anti-slip ribs are formed on the external surface of therotary sleeve 2, the distal end of the rotary sleeve 2 is received bythe main body 1, and the proximal end is received by a receiving member16 provided to the main body 1. In use of a drill driver or other rotarypower tool, rotational force is necessary when opening and closing thechuck or during drilling and other work, but in use of an impact driver,hammer drill, vibration drill, or other rotary power tool, althoughrotational force is also necessary, since a maintenance force in theaxial direction is necessary for retention, a linkage in the form of apatterned knurling provided to the rear end of the main body 1 ispreferred as the linkage between the receiving member 16 and the mainbody 1. The receiving member 16 is exposed on the outside of the rotarysleeve 2 in the present example, but the receiving member 16 may also beaccommodated inside the rotary sleeve 2.

Consequently, a tool is gripped by the jaws 4, and when the rotarysleeve 2 is rotated, until a predetermined load is placed on the rotarysleeve 2, the rotary sleeve 2 and the nut bodies 12 rotate together, andthe engaging spring bodies 22, 23 thereby also rotate on the peripheryof the ratchet teeth 21.

When the rotary sleeve 2 is rotated to a predetermined position (atwhich the jaws 4 abut the tool), a predetermined load acts on the rotarysleeve 2 (in the state shown in FIG. 6), and when the rotary sleeve 2 inthis state is further rotated against the spring force in the directionindicated by the arrow in FIG. 6, the rotary sleeve 2 rotates inrelation to the nut bodies 12, the interposing body 35 which receivesthe distal-end engaging part 24 of the engaging spring body 22 moves,the immobilizing part 32 of the middle sleeve body 10 presses againstthe distal-end engaging part 24 so that the distal-end engaging part 24engages with the ratchet teeth 21, the projections 33, 34 of the middlesleeve body 10 surmount the projections 30, 31 of the engaging springbody 23, the rotation-transmitting engaging parts 9 abut the end surfaceM of the projection 14 b and the end surface N of the projected part 14d, respectively, so that the middle sleeve body 10 (rotary sleeve 2) andthe nut bodies 12 are integrated; and when the rotary sleeve 2 isfurther rotated, the distal-end engaging part 24 of the engaging springbody 22 engaged with the ratchet teeth 21 surmounts the ratchet teeth 21one tooth at a time by a leaf spring effect and engages with apredetermined ratchet tooth 21 (in this state, reverse rotation isprevented by the ratchet teeth 21), the rotation resistance of therotary sleeve 2 increases, and tightening is completed (state shown inFIG. 7).

Tightening is not yet completed in the state in which the teeth aresurmounted one at a time, and when tightening is completed, nosurmounting of teeth occurs.

The tightened state is maintained by the projections 33, 34 andprojections 30, 31.

When the rotary sleeve 2 is rotated in reverse to release the fastenedstate, by the reverse of the operations described above, the projections30, 31 positioned to the right of the projections 33, 34 (in the stateshown in FIG. 7) surmount the projections 33, 34, and when the rotarysleeve 2 is further rotated in the direction of the arrow in FIG. 7, theengagement (meshing) between the distal-end engaging part 24 and theratchet teeth 21 by the immobilizing part 32 is released, theinterposing body 35 furthermore moves and lifts up the distal-endengaging part 24 of the engaging spring body 22, and the fastening ofthe tool is loosened by further rotating the rotary sleeve 2. Thisstate, i.e., the state in which the distal-end engaging part 24 of theengaging spring body 22 and the ratchet teeth 21 are disengaged, is alsomaintained by the projections 33, 34 and the projections 30, 31.

Consequently, loosening of tool fastening is reliably prevented in thechuck device of the present example, and a superior chuck device isobtained which has a simple structure and excellent durability.

The interposing body 35 in the present example is provided to preventthe distal-end engaging part 24 of the engaging spring body 22 fromunexpectedly meshing with the ratchet teeth 21 (consequently, in a statein which the distal-end engaging part 24 is not received by theinterposing body 35, i.e., a state in which the immobilizing part 32does not abut the distal-end engaging part 24, the distal-end engagingpart 24 is kept apart from the ratchet teeth 21 by the elasticity of thespring), but the distal-end engaging part 24 may also be configured sothat the immobilizing part 32 is unnecessary or omitted, the distal-endengaging part 24 is always meshed with the ratchet teeth 21, and meshingof the distal-end engaging part 24 with the ratchet teeth 21 is forciblyreleased by the interposing body 35.

Since the present example is configured as described above, even whenimpact or vibration occurs during work using a gripped tool, the rotarysleeve 2 can be more reliably prevented from separating from the rotarybody 3 or the main body 1.

By providing the co-rotation fitting parts 7 of the retaining engagingbody 5, the middle sleeve body 10 can be provided, and even in a case inwhich the rotary sleeve 2 is made of metal in order to increase thestrength of the external peripheral part to prevent injury due tofriction of the external peripheral part during work, the middle sleevebody 10 is made of synthetic resin, the inside surface (the immobilizingpart 32, the projections 33, 34, or the interposing body 35) and otherparts of the middle sleeve body 10 can easily be molded in the desiredshape, and accordingly excellent workability and mass-productivity areobtained. Since the middle sleeve body 10 and the rotary sleeve 2 areseparate, even when the exterior design of the rotary sleeve 2 ischanged, the middle sleeve body 10 can be diverted so that only therotary sleeve 2 need be replaced. The exterior design of the rotarysleeve 2 can therefore be changed accordingly more easily andinexpensively. The present example is thus a practical chuck devicewhich is not only capable of providing more reliable and stableretention between the rotary body or the main body and the rotarysleeve, but also has excellent mass-productivity.

The invention claimed is:
 1. A chuck device in which a rotary sleeveprovided to a main body is rotated, and the rotation of an annularrotary body which rotates together with the rotary sleeve causes jawsscrewed together with said annular rotary body to expand, contract,advance, and retract, and causes a tool to be gripped by the jaws; saidchuck device comprising: a retaining engaging body for engaging withsaid annular rotary body or said main body and preventing said rotarysleeve from coming out of said annular rotary body or said main body; amiddle sleeve body for fitting with said annular rotary body provided onthe inside of said rotary sleeve; and a rotation transmission part fortransmitting the rotation of said rotary sleeve to said rotary body viasaid middle sleeve body provided to said retaining engaging body,wherein the retaining engaging body is provided so as to be fixed to aproximal end side of said rotary sleeve; the rotation of said rotarysleeve is transmitted to said annular rotary body via said retainingengaging body and said middle sleeve body, and said annular rotary bodyrotates together with said rotary sleeve; and said retaining engagingbody is provided with a co-rotation fitting part as said rotationtransmission part, for fitting with a recessed part or projected partprovided to said middle sleeve body in a fixed manner.
 2. The chuckdevice according to claim 1, wherein said retaining engaging bodycomprises: a cylindrical fixed part fixed to said rotary sleeve; and aprotruding part for preventing said rotary sleeve from coming out of therotary body or the main body, the protruding part protruding toward theinside of the cylindrical fixed part and abutting said rotary body orsaid main body; and said co-rotation fitting part provided to saidcylindrical fixed part.
 3. The chuck device according to claim 2,wherein said protruding part extends in a direction intersecting withthe rotational axis of said rotary sleeve.
 4. The chuck device accordingto claim 3, wherein said co-rotation fitting part extends in therotational axis direction of said rotary sleeve.
 5. The chuck deviceaccording to claim 4, wherein said protruding part and said co-rotationfitting part are provided so that the extension directions thereofintersect each other at substantially a right angle.
 6. The chuck deviceaccording to claim 5, wherein said cylindrical fixed part ispress-fitted on an internal peripheral surface of said rotary sleeve soas to be fixed to said rotary sleeve.
 7. The chuck device according toclaim 6, wherein said retaining engaging body is made of metal, and saidprotruding part, said co-rotation fitting part, and said cylindricalfixed part are formed so as to be integrally molded.
 8. The chuck deviceaccording to any of claims 1 and 2-7, wherein said middle sleeve body isprovided with a rotation-transmitting engaging part disposed between aplurality of projections provided to said annular rotary body, therotation-transmitting engaging part engaging with the projections andtransmitting the rotation of said rotary sleeve to said annular rotarybody.
 9. The chuck device according to claim 8, wherein said rotarysleeve is made of metal, and said middle sleeve body is made ofsynthetic resin.
 10. The chuck device according to claim 9, wherein saidrotary body comprises an annular nut body formed by providing aplurality of split nut bodies in a connected row arrangement, and ashape-retaining ring for retaining the shape of the nut body.